Hearing system and method for generating monaural or binaural beach

Abstract

The hearing system (2) is in particular a binaural hearing system (2) designed to generate monaural or binaural beats and for this purpose comprises at least one hearing aid (4A, 4B) with a main signal path (8). The hearing aid (4A, 4B) further comprises a secondary signal path (26) with a signal generator (28) for generating a first beat signal (B1), wherein the first beat signal (B1) is frequency-shifted by one beat frequency relative to a further signal (B2), such that the effect of the monaural or binaural beat is generated for the user during operation. The signal generator (28) is configured such that the first beat signal (B1) has at least one signal component, referred to as an ambient signal (Su), at least in certain operating modes of the hearing aid (4A, 4B), which is generated on the basis of the electrical input signal (E1) and thus on the basis of the ambient noise.Preferably, the beat signal (B1, B2) is composed of different signal components, the weighting (G) of which is preferably set depending on a signal level of the input signal.

Description

[0001] The invention relates to a hearing system, in particular a binaural hearing system, and to a method for generating monaural or binaural beats using such a hearing system.

[0002] In this context, a hearing system is understood to be a system with at least one hearing aid, and a binaural hearing system is understood to be a system with two hearing aids. Hearing aids are electronic devices that a user wears on the ear, behind the ear, or in the ear. A hearing system is, in particular, a hearing aid system designed to compensate for a user-specific hearing loss in a hearing-impaired person.

[0003] Such a hearing aid usually has an input transducer which first converts an acoustic or streamed input signal into an electrical input signal, which is subsequently processed by means of a particularly digital signal processing unit into an electrical output signal, which is fed to an output transducer which converts the electrical output signal into an acoustic output signal, which is delivered to the ear of the listener.

[0004] Monaural beats or binaural beats are well-known sensory effects in the human brain in which the user perceives a pulsating tone (beat) when presented with two identical acoustic signals with slightly different frequencies. With binaural beats, the user is presented with the two frequency-shifted acoustic signals on two channels, namely the left and right ear. With monaural beats, the two frequency-shifted acoustic signals are presented on only one channel.

[0005] With such monaural or binaural beats, certain training effects for the brain can be achieved.

[0006] Based on this, the invention is based on the object of generating acoustic output signals with the aid of a hearing system which are suitable for producing a pleasant perception of monaural or binaural beats in the user.

[0007] The object is achieved according to the invention by a hearing system, in particular a binaural hearing system having the features of claim 1, as well as by a method for generating monaural or binaural beats using such a hearing system. Advantages and preferred embodiments cited with regard to the hearing system are also applicable to the method, and vice versa.

[0008] The hearing system is, in particular, a hearing aid system that is user-specifically configured and designed to compensate for a user-specific hearing loss.

[0009] The hearing system has at least one hearing aid and preferably, especially when designed as a binaural hearing system, two hearing aids, whereby the at least one hearing aid has a main signal path, with an input transducer for generating an electrical input signal from, for example, an acoustic or streamed input signal, with a particularly digital signal processing unit for processing the electrical input signal and for generating an electrical output signal, as well as with an output transducer which generates an acoustic output signal based on the electrical output signal, the at least one hearing aid further has a secondary signal path, each with a signal generator for generating a first beat signal, wherein the first beat signal is frequency-shifted from another signal by one beat frequency, such that the effect of a monaural or binaural beat is generated during operation by the user, the at least one hearing aid has a summer which sums at least the first beat signal to a signal of the main signal path,so that the acoustic output signal is formed by a normal audio signal component and a beat signal component, the signal generator (28) is connected to the first signal path (8) and is configured such that the first beat signal (B1), at least in certain operating modes of the hearing aid (4A, 4B), has at least one signal component referred to as an ambient signal, which is generated on the basis of the electrical input signal (E1).

[0010] In the case of a binaural hearing system, the two hearing aids each have a communication unit that forms a communication interface through which the two hearing aids communicate with each other and exchange data in a known manner. In particular, a Bluetooth connection is provided for this purpose.

[0011] In a hearing system with two hearing aids, especially a binaural hearing system, the second hearing aid also has a main signal path with the components listed above.

[0012] In a preferred embodiment, but not mandatory, such a second hearing aid also has a secondary signal path, in which a signal generator for generating a second beat signal is also arranged. In this embodiment, the two beat signals are frequency-shifted from each other by the beat frequency. In this case, the second hearing aid also has a summer, which sums the second beat signal to a signal from the first signal path. This also generates an acoustic output signal in the second hearing aid, which is formed by a normal audio signal component and a beat signal component based on the second beat signal.

[0013] The normal audio signal component in the acoustic output signal is understood to be the signal component that would result without the summation of the beat signal.

[0014] In this context, beat frequency is understood to be the frequency by which the two beat signals are frequency-shifted from each other. The beat frequency is typically in the range of 0.5 Hz to 60 Hz, preferably up to a maximum of 55 Hz, and frequently in the range between 3 Hz and 30 Hz.

[0015] To generate the frequency-shifted beat signal, at least one signal generator has a frequency shifter, which shifts a signal generated or provided by the signal generator (e.g. ambient signal, sine signal, narrowband noise, signal component) by the beat frequency and thus generates the frequency-shifted beat signal.

[0016] By using the ambient signal, i.e., the acoustic input signal captured by the input transducer, as the basis for generating the (frequency-shifted) first beat signal, the advantage is achieved that the generation of the beat signals and thus the perception of the beats are based on the ambient noise. This is perceived by the user as particularly pleasant, as it contains no additional, extraneous signal components. At the same time, the desired perception of monaural or binaural beats is still achieved.

[0017] The signal curve of the ambient signal corresponds to the signal curve of at least one selected frequency band of the input signal.

[0018] The design of a secondary signal path in the second hearing aid is not mandatory, even with binaural hearing aids and / or when generating binaural beats.

[0019] When generating monaural beats, for example, only a normal signal component based on the input signal and a frequency-shifted signal component based on the input signal are provided as beat signals within at least one hearing aid, which then lead to the perception of the monaural beats. When generating binaural beats, it is also sufficient in one embodiment if, for example, in the signal generator of the first hearing aid, the first beat signal is generated based on the input signal solely by a frequency shift of the input signal or signal components of the input signal and is provided as the ambient signal. The binaural effect is generated, for example, by the audio signal (acoustic output signal) at the second hearing aid and the frequency-shifted beat signal component (based on the first beat signal) in the acoustic output signal of the first hearing aid.

[0020] In particular, in such variants, a secondary signal path is omitted in the second hearing aid and / or a frequency-shifted beat signal is generated only in the first hearing aid.

[0021] However, the preferred variant is one in which both hearing aids have a signal secondary path and a signal generator each. In this case, the beat signals generated by the respective signal generator in both hearing aids contain at least the ambient signal as a signal component. In one variant, the beat signals consist of the ambient signal. The beat signals, and thus also the ambient signals of the two beat signals, are identical except for the frequency shift around the beat frequency. In some variants, the two beat signals / ambient signals can also differ in terms of their amplitude.

[0022] When referring to a beat signal in this context, this generally refers to a signal that contributes to a signal component in the acoustic output signal that contributes to the desired effect of a monaural or binaural beat. At least in certain operating modes of the hearing aid, these signal components (ambient signal) are based on the ambient noise, i.e., the acoustic input signals.

[0023] According to a preferred embodiment, the at least one hearing aid has an analysis unit for analyzing the input signal, and the beat signal is composed of one or more signal components. The signal generator is configured to compose the beat signal based on the analysis of the input signal.

[0024] The various signal components from which the beat signal is composed, depending on the analysis of the input signal and thus the ambient noise, are preferably selected from the ambient signal, a sine signal, and a particularly narrowband noise signal. Each of these signals therefore forms a possible signal component of the respective beat signal.

[0025] A narrowband noise signal is defined as noise that extends over a frequency band, preferably with a bandwidth of only 100 Hz to 300 Hz. The noise signal is preferably between 250 Hz and 5 kHz.

[0026] These additional signals in addition to the ambient signal can also be generally referred to as carrier signals, which are independent of the input signal.

[0027] Preferably, the respective signal generator has an individual generator part for each signal component that is configured for the signal component.

[0028] The selection of signal components and the composition of the beat signal are preferably determined based on the signal level of the (acoustic) input signal. The respective beat signal can consist of just one signal component, several signal components, or all signal components.

[0029] This design is based on the realization that different types of beat signals are particularly pleasant for the user for different signal levels of the input signal.

[0030] It has been shown that at low signal levels, a single tone, such as a beat signal based on a sine wave, is perceived as more disturbing or unpleasant than, particularly narrowband noise. As the signal level increases, this situation reverses, and the sine wave is perceived as more pleasant. Finally, at higher signal levels, the use of ambient signals is perceived as particularly pleasant, since otherwise, very loud sine waves would have to be generated as additional signals, which would then be perceived as disturbing.

[0031] The signal level of the input signal is generally a characteristic value for the signal level, i.e., the amplitude of the acoustic or streamed input signal detected by the input transducer. The (current) signal level is usually determined based on an evaluation of the converted electrical input signal. Specifically, the determination of the signal level is an estimate. By determining the signal level, an overall signal level and thus an amplitude of the current ambient noise is determined or estimated.

[0032] Different methods can be used to determine the signal level. For example, a broadband signal component of the input signal, such as the entire bandwidth of the audible frequency spectrum, or just a subband is evaluated. In this case, the signal levels in different frequency bands are averaged, and the averaged signal level is considered the signal level of the input signal. Alternatively, the frequency band with the highest signal level is used, and this maximum signal level is considered the signal level of the input signal.

[0033] It is also possible to specify a reference frequency at which the signal level is determined as the reference level and thus as the signal level of the input signal. The reference frequency could be, for example, a center frequency of a selected frequency band or the frequency with the highest signal level. The frequency band and / or the reference frequency can be fixed, for example, or alternatively, determined dynamically based on the current maximum signal level.

[0034] In a further useful development, it is further provided that the signal components are weighted differently depending on the determined signal level. This means that the weighted composition of the respective beat signal changes with the signal level.

[0035] Weighting is preferably understood as the signal level of the respective signal component in the acoustic output signal. If the respective signal component extends across a frequency band, such as in the case of noise or the ambient signal, the weighting is determined by the maximum signal level within the frequency band or, alternatively, by an average signal level within the frequency band.

[0036] The weighting and thus the signal level of the various signal components is adjusted in particular by means of at least one adjustable amplifier element.

[0037] Preferably, the amplifier element has an amplifier subcomponent for each of the signal components in order to be able to adjust the individual weighting factors and thus the amplification factors independently of one another. Conveniently, a respective amplifier subcomponent is assigned to each individual generator part configured for a respective signal component.

[0038] Based on the previously described knowledge in connection with the effect of the various signal components depending specifically on the signal level of the input signal, it is particularly intended that the weighting of the ambient signal increases with increasing signal level.

[0039] Alternatively or additionally, at a low signal level, the weighting of the ambient signal is lower than that of the other signal components, particularly than each of the other signal components individually. As the signal level increases, the weighting of the ambient signal increases and eventually exceeds the other signal components, for example, in a medium level range.

[0040] In a preferred embodiment, the noise signal is given the highest weighting in a lower, quiet level range of the input signal, the sine signal in a medium level range, and the ambient signal in a high level range. Overall, this results in a qualitative weighting curve in which, at a quiet signal level, the narrowband noise dominates, followed by the sine signal in a medium level range, and finally, the ambient signal dominates at a high level range. A quiet signal level is understood to be a signal level up to 50 dBSPL or up to 55 dBSPL (decibel sound pressure level). A medium signal level is understood to be a level range between 50 / 55 dBSPL and 75 dBSPL or up to 80 dBSPL, and a loud signal level is understood to be a level above 75 dBSPL or even above 80 dBSPL.

[0041] In a preferred embodiment, the analysis is carried out repeatedly and, in particular, continuously and continuously. The time interval between two consecutive analysis steps is preferably less than 300 ms and is, for example, 100 ms. The time interval is generally preferably between 100 ms and 300 ms. Based on each of these continuously and repeatedly performed analyses, the composition of the beat signal is then adapted depending on the current analysis, i.e., the composition of the beat signal and thus the weighting of the various signal components changes over time. The composition is therefore continuously adjusted to the level curve of the input level.

[0042] In addition to analyzing and determining the signal level of the input signal, additional parameters are preferably used to determine the composition of the beat signal. Such parameters include, for example, the current state of the respective user, such as heart rate, movements or accelerations of body parts, etc. These parameters are derived either using an additional device or indirectly from the input signals. This design is based on the consideration that even in certain user states, such as sleeping, exercising, etc., different signal components are more or less suitable for the desired effect.

[0043] In a practical design, the ambient signal is a band-filtered ambient signal. The hearing aid accordingly also has a suitable band-filter, so that the ambient signal is filtered out of the detected input signal and has a predetermined bandwidth. This is based on the consideration that only a certain frequency range is particularly suitable for generating the perception of beats.

[0044] Preferably, the band-filtered ambient signal has a bandwidth in the range of 100 Hz to 400 Hz. Furthermore, the ambient signal preferably lies in a middle band range between 200 Hz and 1000 Hz, and in particular has the aforementioned bandwidth.

[0045] According to a preferred embodiment, parameters of the band-filtered ambient signal, such as bandwidth, center frequency, or lower or upper band frequency, are adjusted depending on a user-specific audiogram, i.e., depending on a user-specific hearing loss. Specifically, the bandwidth and / or center frequency are selected such that they are outside a frequency band where the user has significant hearing deficits compared to other frequency bands, where high amplification is required.

[0046] The frequency band of the ambient signal is therefore placed in a frequency range where a comparatively low user-specific amplification is required.

[0047] In a suitable embodiment, the hearing system is configured such that the values ​​of the parameters of the band-filtered ambient signal, such as bandwidth, mean frequency, or lower or upper band frequency, vary over time and in particular depending on the current input signal. The parameter values ​​are selected, for example, depending on the signal level. Specifically, a mean frequency of the ambient signal is selected such that it lies outside a frequency or frequency band with the highest signal level of the input signal. This serves to avoid masking effects.

[0048] Overall, the band-filtered ambient signal is therefore a dynamic ambient signal over time, the parameter values ​​of which vary, in particular depending on the input signal, especially depending on the signal level of the input signal.

[0049] In a preferred development, an adjustment device is preferably assigned to the respective signal generator in each hearing aid, wherein the adjustment device comprises the above-described adjustable amplifier element. The aforementioned analysis unit is also part of this adjustment device. Furthermore, the adjustment device is configured to adjust a signal level of at least the first beat signal and preferably of both beat signals depending on a current, instantaneous signal level of the input signal.

[0050] This measure ensures that the signal level of the beat signal is continuously adjusted to the current signal level of the input signal. The analysis and the corresponding adjustment of the signal level of the beat signals are preferably performed in time periods of less than 500 ms, for example, every 100 ms.

[0051] The tracking of the signal level of the beat signal leads to a particularly pleasant perception of the monaural or binaural beats.

[0052] In a preferred embodiment, the hearing system has a user-specific adjustment element, via which a manual adjustment of the beat signal, in particular the signal level of the beat signal, is possible. For this purpose, the hearing system has, for example, a control interface, in particular in the form of a portable device such as a smartphone, on which an application is installed, via which settings for the respective hearing aid can be made. This portable device is part of the hearing system. Alternatively or additionally, control elements can also be arranged directly on at least one hearing aid, via which the adjustment can be made.

[0053] These manual adjustment options therefore offer the user the opportunity to at least fine-tune parameters that influence the beats themselves in order to achieve the most pleasant listening experience possible. These parameters include, in particular, the beat frequency and / or the gain factor for the amplifier element, or the signal level of the respective beat signal, especially the level difference compared to the normal audio signal component in the acoustic output signal.

[0054] In a preferred development, the hearing system has a status detector, i.e., it is designed to automatically detect a current status of the user. Furthermore, the hearing system, in particular the adjustment device, is configured to adjust the at least one beat signal depending on the identified current status. The status of the user is understood to mean, in particular, a current physical state of the user, which is determined, for example, by determining the user's current pulse and / or by acceleration sensors. The current status can be determined either with auxiliary devices or directly with the aid of the hearing aid. For example, acceleration sensors can be integrated into the hearing aid, or the hearing aid can be designed to determine the hearing aid wearer's current pulse from acoustic signals, e.g., structure-borne sound signals.

[0055] In particular, a sleep mode is identified, particularly in comparison to a wake mode, with the parameters then being set differently for the different modes. Parameters for the beat signal, in turn, include, in particular, the beat frequency (i.e., the magnitude of the frequency shift between the beat signals) and / or the signal level. For example, in an identified sleep mode, the signal level is reduced compared to a wake mode. In addition or alternatively, different beat frequencies are set for the wake mode and the sleep mode. It is known that different beat frequencies have different effects and training effects on the brain.

[0056] In a preferred embodiment, the beat frequency is set to a range between 35 Hz and 45 Hz, for example, in sleep mode, and especially to 40 Hz. Studies have shown that such beat frequencies offer particular advantages, especially in sleep mode.

[0057] Embodiments of the invention are explained in more detail below with reference to the figures, in which FIG 1 shows a simplified block diagram of a variant of a binaural hearing system to explain the tracking of a signal level of beat signals depending on the signal level of an input signal, FIG 2 shows a partial representation based on the hearing system according to FIG 1 to explain the composition of the beat signals from various signal components, as well as FIG 3 a representation of a qualitative course of the weighting of the various signal components as a function of the signal level of the input signal.

[0058] One in FIG 1 The hearing system 2 shown is designed as a hearing aid system configured to compensate for a user-specific hearing loss. It is a binaural hearing system 2 with two hearing aids 4A, 4B, each of which communicates with each other in a conventional manner via a wireless communication unit (not shown in detail here), in particular a Bluetooth communication interface. The two hearing aids 4A, 4B are at least largely identical in design. Any differences will be explicitly addressed.

[0059] Each hearing aid 4A, 4B has one or more input transducers 6, in particular microphones, via which an input signal, in particular an acoustic ambient signal, is converted into an electrical input signal E1, E2. This is initially processed in a main signal path 8 and in a signal processing unit 10 in a manner known per se, specifically based on a user-specific audiogram and thus in accordance with a user-specific hearing loss. The processed electrical signal is fed as an electrical output signal A1, A2 to an output transducer 12, which converts the electrical output signal into an acoustic output signal aA1, aA2. The output transducer 12 is, in particular, a loudspeaker.

[0060] The signal processing unit 10 has, for example, a filter bank 14 on the input side, via which the electrical input signal E1, E2 is broken down into different frequency bands for subsequent signal processing. Typically, several signal processing units 16, 18 are provided downstream, such as a beamformer for generating directionality or a noise suppressor for reducing disruptive ambient noise. An electrical input signal E1, E2 partially processed by the signal processing units 16, 18 is then fed to a summer 20. A signal amplifier 22, typically with an integrated compression unit, is arranged downstream of the summer 20. Finally, the signal amplifier 22 is followed, for example, by a synthesizing filter bank 24, which recombines the individual frequency bands and at the end of which the electrical output signal A1, A2 is output.

[0061] In addition to the main signal path 8, each hearing aid 4A, 4B has a secondary signal path 26. This has a signal generator 28 for generating a beat signal B1, B2. In addition to the electrical input signal E1, E2, a further signal is provided via the signal generator 28. This is in particular a signal independent of the input signal, specifically a sinusoidal signal or a particularly narrowband noise signal. It is also possible to use a signal component of the electrical input signal E1, E2 received by the input transducer 6, i.e., ambient noise, as the basis for the beat signal B1, B2. The beat signal B1, B2 is composed, for example, of several signal components formed on the basis of or by the aforementioned signals (sinusoidal signal, noise signal, ambient noise).

[0062] At least one of the two signal generators 28, in the exemplary embodiment in the first hearing aid 4A, incorporates a frequency shifter 30, which shifts the previously generated signal (e.g., sine signal, noise signal) by one beat frequency. The two beat signals B1, B2 are therefore two identical signals with the same signal components, shifted from each other only by the beat frequency.

[0063] Furthermore, each hearing aid 4A, 4B has an analysis unit 32 configured to determine, in particular estimate, a current signal level L m of the (acoustic) input signal. For this purpose, the analysis unit 32 appropriately evaluates the electrical input signal E1, E2 present in front of the adder 20 and possibly partially processed.

[0064] Depending on the instantaneous, currently applied signal level L m determined in this way, a current amplification factor is determined, with which the respective beat signal B1, B2 is amplified. An amplifier element 34 is arranged for amplification. The analysis unit 32 and the amplifier element 34 are components of an adjustment device 36, via which a respective signal level Ls for the beat signal B1, B2 is adjusted.

[0065] According to a preferred embodiment, as shown in the figure, a synchronizer 38 is arranged in at least one of the hearing aids 4A, 4B, which is connected to the two analysis units 32 and receives information about the respective signal level L m from them. This information is transmitted from one hearing aid 4B to the synchronizer 38 arranged in the other hearing aid 4A, in particular, via the previously described communication interface of the binaural hearing system 2.

[0066] The synchronizer 38 evaluates the two instantaneous signal levels L m , in particular, compares them, and, based on this evaluation, determines suitable, synchronized gain factors for the two beat signals B1, B2. In the case of significantly different instantaneous signal levels L m , the synchronizer 38 particularly ensures that the differences in the signal levels LB of the beat signals B1, B2 are limited.

[0067] In an alternative, simplified embodiment not shown in detail here, each adjustment device 36 of the two hearing aids 4A, 4B individually determines a respective instantaneous amplification factor for the respective beat signal B1, B2. Therefore, in this variant, the synchronizer 38 and synchronization are omitted.

[0068] The respectively amplified beat signal B1, B2 is then fed to the summer 20. Subsequently, the resulting composite signal, which includes the partially processed input signal E1, E2 and the beat signal B1, B2 as signal components, is fed to the signal amplifier 22, amplified there, and finally provided after the synthesizing filter bank 24 as the outgoing electrical output signal A1, A2, which is subsequently converted by the output converter 12 into the acoustic output signal aA1, aA2.

[0069] The respective acoustic output signal aA1, aA2 is therefore composed of a normal audio signal component and a beat signal component. The normal audio signal component is the signal component that would result without the respective beat signal components. The beat signal components in the acoustic output signal aA1, aA2 are frequency-shifted from each other by the beat frequency and may have different amplitudes, but are otherwise identical.

[0070] In addition to the normal audio signal, the user is therefore provided with two (acoustic) beat signals B1, B2, offset from each other by the beat frequency, at both of his ears, so that the binaural beats are perceived by the user as desired.

[0071] The instantaneous signal level L m is preferably recorded continuously and preferably at time intervals of less than 300 ms, for example, every 100 ms. The signal level LB of the beat signals B1, B2 is continuously adjusted based on the recorded instantaneous signal levels L m. This is preferably done in such a way that a higher signal level LB of the beat signal components is established in the acoustic output signal aA1, aA2 compared to the signal levels L m of the normal audio signal component. The signal level LB of the beat signal components is preferably 1 dB to 5 dB higher, and in particular 3 dB higher.

[0072] In this case, the electrical input signals across the entire main signal path 8 are uniformly provided with the reference symbols E1, E2, regardless of their processing status.

[0073] In the present case, the further (beat) signals provided by the respective signal generator 28 are uniformly designated with the respective reference symbols B1, B2 over the entire signal path and thus in different processing stages.

[0074] Figur 2 shows a partial, enlarged view of the hearing system 2 in the area of ​​the secondary signal path 26.

[0075] When designing according to the FIG 2 The beat signals B1 and B2 are composed of different signal components. The weighting G of the different signal components is determined depending on the signal level L m of the acoustic input signal.

[0076] For this purpose, the signal generator 28 is initially divided into several generator parts 28A, 28B, and 28C. Additionally, the amplifier element 34 is also divided into several individually adjustable amplifier subcomponents 34A, 34B, and 34C. The various generator parts 28A to 28C are configured to generate different signals as the signal components. These are, in particular, an ambient signal Su, a sinusoidal signal Ss, and a narrowband noise signal SN.

[0077] The generator section 28A serves to generate the ambient signal Su. For this purpose, it is supplied with the electrical input signal E1, E2 on the input side. It has, for example, an integrated bandpass filter 40, so that a narrowband signal component is extracted from the input signal E1, E2, which then forms the ambient signal Su.

[0078] The generator parts 28A-28C of the two hearing aids 4A, 4B are designed identically to one another with the difference that a frequency shifter 30, not explicitly shown here, is additionally integrated into the generator parts 28A to 28C of the first hearing aid 4A in order to generate the desired frequency shift around the beat frequency.

[0079] The generator parts 28B, 28C each generate independent signals independent of the electrical input signal E1, E2.

[0080] The various signal components Su, SN, Ss are individually amplified via the respective amplifier subcomponents 34A to 34C, which are assigned to a respective generator part 28A to 28C. These are subsequently combined in a combiner 42, which is designed in particular as a summer, and then form the respective beat signal B1, B2, which is fed to the summer 20 in the main signal path 8.

[0081] The individual gain factors for the various signal components Su, SN , Ss are set depending on the signal level LM of the input signal. For this purpose, as already described for FIG 1 As described, an analysis unit 32 is integrated in each hearing aid 4A, 4B, which is designed to determine and in particular estimate the incoming signal level LM.

[0082] In FIG 2 is analogous to FIG 1 a variant with the synchronizer 38 is shown. This in turn serves for the synchronized control of the amplifier element 34. The basic features are the same as for FIG 1 described. In contrast to FIG 1 Now, however, the amplifier subcomponents 34A to 34C are each individually controlled, so that different amplification factors and thus weightings G are set for the different signal components SU, SN, SS. This means that the different signal components Su, SN, Ss are weighted differently in the then combined beat signal B1, B2. The signals B1, B2 then each have a signal level LB. The amplification factors for the signal components SU, SN, SS are selected in a suitable manner such that the desired value for the signal level Ls is achieved, as is particularly the case in connection with the FIG 1 was described.

[0083] In an alternative embodiment, the synchronizer 38 is omitted and the setting of the weightings G is carried out in the two hearing aids, for example, independently of one another and on the basis of the signal level L m determined by the analysis unit 32 of the respective hearing aid 4A, 4B.

[0084] FIG 3 shows the qualitative weighting of the various signal components SU, SN, SS as a function of the input signal level L m . The x-axis represents the signal level LM (increasing from left to right), and the y-axis represents the weighting G and thus the amplification of the various signal components SU, SN, SS.

[0085] As can be clearly seen from this, at a low, quiet signal level L m the noise signal SN dominates, the weighting G of which decreases with increasing signal level L m , preferably in the manner of a hyperbola, which asymptotically approaches a minimum value, which is preferably 0 or alternatively not equal to 0.

[0086] At the low, quiet signal level L m , the sinusoidal signal Ss still has a high weighting factor compared to the ambient signal Su , but this is lower than that of the noise signal SN . The weighting factor of the sinusoidal signal SS decreases with increasing signal level L m , preferably linearly.

[0087] In general, the noise signal SN decreases more sharply than the sinusoidal signal Ss with increasing signal level L m, so that their two curves intersect, so that in a medium level range the sinusoidal signal Ss dominates.

[0088] In contrast to these two signal components SN and Ss, the ambient signal Su increases with increasing signal level L m. The increase is, for example, exponential.

[0089] In the low, quiet level range, the ambient signal Su starts at a constant value, in particular at 0, so that in the quiet level range the beat signal B1, B2 is composed exclusively of the two other signal components SS, SN.

[0090] In the middle level range, the respective beat signal B1, B2 is composed of all three signal components Su, SN, Ss, with the weighting varying within the middle level range. The beginning of the middle level range is considered to be the intersection of the weighting curves of the signal components Ss, SN.

[0091] In the middle level range, the weighting of the ambient signal Su increases progressively, initially exceeding, for example, the weighting of the noise signal SN and later also the weighting of the sinusoidal signal Ss. The signal level L m , at which the largest weighting component is formed by the ambient signal Su, is defined here as the end of the middle control range. In this case, it is the intersection point between the weighting curve of the sinusoidal signal Ss and the ambient signal Su.

[0092] In the high level range following the middle level range, the weighting G of the ambient signal Su continues to increase, while the weighting of the other two signals SN, SS continues to decrease and in particular even goes back to 0. In high control ranges, therefore, the ambient signal Su is predominantly present (greater than 75% of the total level) or even exclusively, so that the respective beat signal B1, B2 is formed predominantly or exclusively by the ambient signal Su.

[0093] The different weighting of the various signal components Su, SN, Ss depending on the signal level L m is based on the knowledge that the various signal components Su, SN, Ss are perceived differently depending on the signal level L m. Studies have shown that at low signal levels, a pure sine tone is perceived as unpleasant, whereas in a medium level range, it is perceived as more pleasant than a noise signal. At high control ranges, the use of the ambient signal Su as a signal component has proven particularly advantageous.

[0094] The previously mentioned units, such as filter bank 14, 24, signal processing unit 16, 18, summer 20, signal amplifier 22, signal generator 28 with generator parts 28A-28C, frequency shifter 30, analysis unit 32, amplifier element 34 with amplifier subcomponents 34A-34C, synchronizer 38, and bandpass filter 40, are each electronic components or groups of electronic circuit components that implement the desired described functions during operation. These units are integrated, for example, in one or more integrated circuits, microchips, and / or ASICs. List of reference symbols

[0095] 2 Hearing system 4A, B Hearing aid 6 Input transducer 8 Main signal path 10 Signal processing unit 12 Output transducer 14 Filter bank 16 Signal processing unit 18 Signal processing unit 20 Summer 22 Signal amplifier 24 Synthesizing filter bank 26 Secondary signal path 28 Signal generator 28 A- C Generator parts 30 Frequency shifter 32 Analysis unit 34 Amplifier element 34 A- C Amplifier subcomponent 36 Adjustment device 38 Synchronizer 40 Bandpass filter E1, E2electrical input signal A1, A2electrical output signal aA1, aA2acoustic output signal B1, B2beat signal L m signal level of the input signal LB signal level of the beat signal Suambient signals Sssine signal SN noise signal Gweighting

Claims

1. Hearing system (2), in particular a binaural hearing system (2), which is designed to generate monaural or binaural beats, with at least one hearing aid (4A, 4B), wherein - the at least one hearing aid (4A, 4B) has a main signal path (8), with an input transducer (6) for generating an electrical input signal (E1, E2) from a particularly acoustic input signal, with a signal processing unit (10) for processing the electrical input signal (E1, E2) and for generating an electrical output signal (A1, A2), and with an output transducer (12) which generates an acoustic output signal (aA1, aA2) based on the electrical output signal (A1, A2), - the at least one hearing aid (4A, 4B) further has a secondary signal path (26), with a signal generator (28) for generating a first beat signal (B1), wherein the first beat signal (B1) is converted to a further signal (B2) is frequency shifted by one beat frequency, such thatthat during operation the effect of the monaural or binaural beat is generated for the user, - the at least one hearing aid (4A, 4B) has a summer (20) which sums at least the first beat signal (B1) to a signal of the main signal path (8), wherein - the signal generator (28) is connected to the first signal path (8) and is configured such that the first beat signal (B1), at least in certain operating modes of the hearing aid (4A, 4B), has at least one signal component referred to as an ambient signal (Su), which is generated on the basis of the electrical input signal (E1).

2. Hearing system (2) according to the preceding claim, which is designed as a binaural hearing system (2) and for generating binaural beats, with the at least one first hearing aid (4A) and with a second hearing aid (4B), which are designed for wireless, binaural communication with each other, wherein - each of the hearing aids (4A, 4B) has a main signal path (8), with an input transducer (6) for generating an electrical input signal (E1, E2), with a signal processing unit (10) for processing the input signal (E1, E2) and for generating an electrical output signal (A1, A2), and with an output transducer (12) which generates an acoustic output signal (aA1, aA2) based on the electrical output signal (A1, A2), - each of the hearing aids (4A, 4B) further has a secondary signal path (26),each having a signal generator (28) for generating the first beat signal (B1) in the first hearing aid (4A) and a second beat signal (B2) in the second hearing aid (4B), wherein the two beat signals (B1, B2) are frequency-shifted from one another by one beat frequency, such that during operation the effect of a binaural beat is generated for the user, - each of the hearing aids (4A, 4B) has a summer (20) which sums the beat signals (B1, B2) to a signal of the main signal path (8), wherein - each of the signal generators (38) is connected to the first signal path (8) and is configured such that the beat signal (B1, B2), at least in certain operating modes of the hearing aid (4A, 4B), has at least one signal component referred to as an ambient signal (Su), which is generated based on the electrical input signal (E1, E2).

3. Hearing system (2) according to one of the preceding claims, in which the at least one hearing aid (4A, 4B) has an analysis unit for analyzing the input signal and the beat signal (B1, B2) consists of one or more signal components (S U , S N , S S ), wherein the signal generator (38) is arranged to carry out the composition of the beat signal (B1, B2) on the basis of the analysis of the input signal, wherein the signal components (Su, S N , Ss) are preferably selected from a sinusoidal signal (Ss), a particularly narrowband noise signal (S N ) and the ambient signal (Su) derived from the electrical input signal.

4. Hearing system (2) according to the preceding claim, wherein the analysis unit (32) for analyzing a signal level (L m ) of the input signal and the composition of the beat signal (B1, B2) is carried out on the basis of the analysis of the input signal 5. Hearing system (2) according to the preceding claim, in which, depending on the signal level (L m ) a different weighting (G) of the signal components (S U , S N , S S ), whereby the weighting (G) of the ambient signal (Su) increases with increasing signal level (L m ) preferably increases.

6. Hearing system (2) according to the preceding claim, in which at low signal levels (L m ) the weighting (G) of the ambient signal (Su) is lower than the weighting (G) of each of the other signal components (S N , S S ).

7. Hearing system (2) according to one of the two preceding claims, in which in a quiet control range of the signal level (L m ) the noise signal (S N ), in a medium control range the sine signal (Ss) and in a high control range the ambient signal (Su) is given the highest weight.

8. Hearing system (2) according to one of claims 4 to 7, wherein the analysis is carried out repeatedly and the signal generator (28) is arranged to adapt the composition of the beat signal (B1, B2) depending on the current analysis.

9. Hearing system (2) according to one of claims 4 to 8, in which in addition to the signal level (L m ) further parameters as evaluation criteria for the composition of the beat signal (B1, B2) and the weighting (G) of the signal components (S U , S N , S S ) can be used.

10. Hearing system (2) according to one of the preceding claims, wherein the at least one hearing aid (4A, 4B) has a band filter (40) for generating a band-filtered ambient signal (Su), wherein the ambient signal (Su) has a bandwidth in the range of preferably 100 Hz to 400 Hz and / or wherein the ambient signal (Su) is preferably in a middle band range between 200 Hz and 1000 Hz.

11. Hearing system (2) according to one of claims 9 to 10, in which parameters of the band-filtered ambient signal (Su), such as bandwidth, mean frequency or lower or upper band frequency, are set as a function of a user-specific audiogram and / or the parameters of the band-filtered ambient signal (Su) vary over time and in particular as a function of the instantaneous input signal.

12. Hearing system (2) according to one of the preceding claims, in which the signal generator (28) is assigned an adjusting device (36) which has an adjustable amplifier element (34), wherein the adjusting device (36) has an analysis unit (32) for determining a current signal level (L m ) of the input signal, wherein the respective setting device (36) is adapted to set a signal level (L B ) of the first beat signal (B1) depending on a current signal level (L m) of the input signal (E1, E2).

13. Hearing system (2) according to one of the preceding claims, characterized in that it is designed for manual adjustment of the at least one beat signal (B1, B1) by the user 14. Hearing system (2) according to one of the preceding claims, characterized in that it is designed to automatically identify a current status of the user, in particular a sleep state of the user, and that it is designed to adjust the at least one beat signal (B1, B2) depending on the identified current status.

15. A method for generating monaural or binaural beats in a hearing system (2) with at least one hearing aid (4A, 4B), wherein - the at least one hearing aid (4A, 4B) has a main signal path (8) with an input transducer (6) which generates an electrical input signal (E1, E2) from a particularly acoustic input signal, with a signal processing unit (10) which processes the electrical input signal (E1, E2) and generates an electrical output signal (A1, A2), and with an output transducer (12) which generates an acoustic output signal (aA1, aA2) based on the electrical output signal (A1, A2), - the at least one hearing aid (4A, 4B) further has a secondary signal path (26), each with a signal generator (28) which generates a first beat signal, wherein the first beat signal is frequency-shifted from a further signal by one beat frequency, such thatthat during operation the effect of the monaural or binaural beat is generated for the user, - the at least one hearing aid (4A, 4B) has a summer (20) which sums at least the first beat signal to a signal of the first signal path, wherein - the beat signal (B1, B2), at least in certain operating modes of the hearing aid (4A, 4B), has at least one signal component referred to as an ambient signal, which is generated on the basis of the electrical input signal (E1, E2).,

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